(PECL ds >= 1.0.0)
Ds\Set::reduce — Reduces the set to a single value using a callback function
Reduces the set to a single value using a callback function.
callbackcarry
The return value of the previous callback, or initial if
it's the first iteration.
valueThe value of the current iteration.
initial
The initial value of the carry value. Can be null.
The return value of the final callback.
Ejemplo #1 Ds\Set::reduce() with initial value example
<?php
$set = new \Ds\Set([1, 2, 3]);
$callback = function($carry, $value) {
return $carry * $value;
};
var_dump($set->reduce($callback, 5));
// Iterations:
//
// $carry = $initial = 5
//
// $carry = $carry * 1 = 5
// $carry = $carry * 2 = 10
// $carry = $carry * 3 = 30
?>El resultado del ejemplo sería algo similar a:
int(30)
Ejemplo #2 Ds\Set::reduce() without an initial value example
<?php
$set = new \Ds\Set([1, 2, 3]);
var_dump($set->reduce(function($carry, $value) {
return $carry + $value + 5;
}));
// Iterations:
//
// $carry = $initial = null
//
// $carry = $carry + 1 + 5 = 6
// $carry = $carry + 2 + 5 = 13
// $carry = $carry + 3 + 5 = 21
?>El resultado del ejemplo sería algo similar a:
int(21)